So-called IC tag, which is a contactless electronic device mounting a semiconductor integrated circuit device and an antenna inside, performs information exchanges between a reader/writer device and the semiconductor integrated circuit device, and it realizes various functions such as data transfer of data retained by the IC tag and data retention of data transmitted from the reader/writer device. More particularly, the semiconductor integrated circuit device mounted in the IC tag receives carrier signals supplied from the reader/writer device by the antenna, and rectifies and smoothes an voltage generated between both ends of the antenna, so that an internal voltage required for operating internal circuits is formed, and the semiconductor integrated circuit device superimposes data to the carrier signal supplied from the reader/writer device as well, thereby performing data exchanges.
As for such an IC tag, Japanese Patent Application Laid-Open Publication No. 2005-173790 (Patent Document 1) discloses a technique for essentially eliminating frequency restrictions of the carrier radio waves by generating internal clocks inside the IC tag. In addition, ISO/IEC 18000-6 (Non-Patent Document 1) and ISO/IEC 15693 (Non-Patent Document 2) list various basic specifications of IC tags as standards.